Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 3e352aa8 authored by Tejun Heo's avatar Tejun Heo
Browse files

x86, percpu: Fix DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() 



DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() put percpu variables in
.page_aligned section without adding any alignment restrictions.
Currently, this doesn't cause any problem because all users of the
macros have explicit page alignment and page-sized but it's much safer
to enforce page alignment from the macros.  After all, it's what they
claim to do.

Add __aligned(PAGE_SIZE) to DECLARE/DEFINE_PER_CPU_PAGE_ALIGNED() and
drop explicit alignment from it users.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
parent ed8d9adf

arch/x86/kernel/cpu/common.c

+1 −2
Original line number Diff line number Diff line
@@ -1008,8 +1008,7 @@ static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { 
};



static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks

	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ])

	__aligned(PAGE_SIZE);

	[(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]);



/* May not be marked __init: used by software suspend */

void syscall_init(void)

include/linux/percpu-defs.h

+5 −3
Original line number Diff line number Diff line
@@ -70,10 +70,12 @@ 
 * Declaration/definition used for per-CPU variables that must be page aligned.

 */

#define DECLARE_PER_CPU_PAGE_ALIGNED(type, name)			\

	DECLARE_PER_CPU_SECTION(type, name, ".page_aligned")

	DECLARE_PER_CPU_SECTION(type, name, ".page_aligned")		\

	__aligned(PAGE_SIZE)



#define DEFINE_PER_CPU_PAGE_ALIGNED(type, name)				\

	DEFINE_PER_CPU_SECTION(type, name, ".page_aligned")

	DEFINE_PER_CPU_SECTION(type, name, ".page_aligned")		\

	__aligned(PAGE_SIZE)



/*

 * Intermodule exports for per-CPU variables.